stop recommending bundling at all (or any other workaround)

[springmeyer]

With node versions > 4 all npm versions should be able to install node-pre-gyp correctly before needing to call it.

/cc @mapbox/core-tech

Avoids errors like:

npm ERR! node v6.0.0
npm ERR! npm  v3.8.6
npm ERR! path /Users/carol/dev/api-maps/node_modules/.staging/abbrev-2108b53f
npm ERR! code ENOENT
npm ERR! errno -2
npm ERR! syscall rename

npm ERR! enoent ENOENT: no such file or directory, rename '/Users/carol/dev/api-maps/node_modules/.staging/abbrev-2108b53f' -> '/Users/carol/dev/api-maps/node_modules/@mapbox/vt_shaver/node_modules/abbrev'

Note abbrev is one package that this would happen with, but it seems like any package that would bundled would look like the culprit.